Dual tube frangible joint

Abstract

A frangible joint for separating a pair of components is provided. The frangible joint includes a first portion coupled one of the pair of components and a second portion coupled to the other of the pair of components. The first portion and the second portion are spaced apart by a gap. At least one plate is coupled between the first portion and the second portion across the gap. A first tube having a first explosive cord is disposed therein and a first pliable member arranged between the first explosive cord and the first tube, the first tube being disposed in the gap. A second tube having a second explosive cord is disposed therein and a second pliable member arranged between the second explosive cord and the second tube, the second tube being disposed in the gap adjacent the first tube.

1 . A frangible joint comprising:
 a first portion;   a second portion, the first portion and the second portion being spaced apart to define a gap;   a first explosive cord within the gap adjacent the first portion;   a first pliable member disposed about the first explosive cord;   a first sheath disposed about the first pliable member;   a second explosive cord within the gap and positioned between the first sheath and the second portion;   a second pliable member disposed about the second explosive cord; and,   a second sheath disposed about the second pliable member.   
     
     
         2 . The frangible joint of  claim 1  further comprising a spacer member arranged between the first sheath and the second sheath. 
     
     
         3 . The frangible joint of  claim 1  further comprising a tube member positioned in the gap, wherein the first sheath and the second sheath are arranged within the tube member. 
     
     
         4 . The frangible joint of  claim 3  further comprising a spacer member arranged between the first sheath and the second sheath. 
     
     
         5 . The frangible joint of  claim 1  further comprising first plate coupled between a first side of the first portion and the second portion, and a second plate coupled between a second side of the first portion and the second portion. 
     
     
         6 . The frangible joint of  claim 5  wherein the first plate and the second plate each include a groove. 
     
     
         7 . The frangible joint of  claim 5  further comprising a strap member coupled between the first plate and the second sheath. 
     
     
         8 . The frangible joint of  claim 1  wherein the first pliable member and the second pliable member are each made from rubber. 
     
     
         9 . A frangible joint for separating a pair of components, the frangible joint comprising:
 a first portion coupled one of the pair of components;   a second portion coupled to the other of the pair of components, the first portion and the second portion being spaced apart with a gap therebetween;   at least one plate coupled between the first portion and the second portion across the gap;   a first tube having a first explosive cord disposed therein and a first pliable member arranged between the first explosive cord and the first tube, the first tube being disposed in the gap; and,   a second tube having a second explosive cord disposed therein and a second pliable member arranged between the second explosive cord and the second tube, the second tube being disposed in the gap adjacent the first tube.   
     
     
         10 . The frangible joint of  claim 9  wherein the first pliable member and the second pliable member are made from rubber. 
     
     
         11 . The frangible joint of  claim 9  wherein the first tube and the second tube are made from stainless steel. 
     
     
         12 . The frangible joint of  claim 9  further comprising a spacer disposed between the first tube and the second tube. 
     
     
         13 . The frangible joint of  claim 12  wherein the spacer is integral with the first tube. 
     
     
         14 . The frangible joint of  claim 12  wherein the spacer is transverse to the at least one plate across the gap. 
     
     
         15 . The frangible joint of  claim 9  further comprising a third tube disposed within the gap, wherein the first tube and the second tube are disposed within the third tube. 
     
     
         16 . A method of separating a first component from a second component with a frangible joint, the method comprising:
 providing a first tube having a first explosive cord disposed therein and a first pliable member arranged between the first explosive cord and the first tube;   providing a second tube having a second explosive cord disposed therein and a second pliable member arranged between the second explosive cord and the first tube;   detonating the first explosive cord;   waiting a predetermined amount of time; and,   detonating the second explosive cord when the first explosive cord does not explode.   
     
     
         17 . The method of  claim 16  further comprising arranging a spacer between the first tube and the second tube. 
     
     
         18 . The method of  claim 16  further comprising providing a third tube and disposing the first tube and the second tube in the third tube. 
     
     
         19 . The method of  claim 16  further comprising providing at least one plate and coupling the second tube to the at least one plate with a strap. 
     
     
         20 . The method of  claim 16  wherein the first pliable member and the second pliable member are made from rubber.